The present invention relates to an improved junction adapter for use with a conventional plural line clamping system in which the adapter has a hexagonally shaped body and is formed from hexagonal bar stock.
Plural line clamping systems are widely used in the hydraulics industry whenever it is necessary to connect plural fluid lines to a machine. Such a clamping system provides a mounting device for holding the junction adapters that connect the fluid lines from the machine to the fluid lines heading to the source of fluid power. The plural line clamping system provides a secure mount for fluid line junction adapters over a wide range of fluid line pressures that resists the forces tending to cause the junction adapter to shake loose or rattle. Plural line clamping systems are disclosed in U.S. Pat. Nos. 3,397,431, 3,414,220, and 4,878,696, all issued in the name of William R. Walker and assigned to the assignee of present invention, namely, Hydro-Craft, Inc., of Rochester Hills, Mich. These patents, which also show prior art junction adapters, are hereby incorporated by reference.
Since their introduction, plural line clamping systems such as those available from Hydro-Craft, Inc. and sold under the trademark "MULTI-CLAMP", have become quite popular and are widely used in the machine tool industry to route and secure hydraulic and pneumatic piping, tubing and other lines in an orderly, neat and efficient manner. The plural line clamping system in general provides a simple and sturdy mount for the junction adapters and is widely used in almost any hydraulics application where it is necessary to have plural fluid lines. There are currently several tens of thousands of MULTI-CLAMP.RTM. installations in use in the United States and other countries, and MULTI-CLAMP.RTM. assemblies in several standard sizes have been sold for years by the assignee.
The basic arrangement of a common plural line clamping system can be seen from reviewing the above-cited patents or by reviewing the prior art FIGS. 1 and 2. As can be seen in FIG. 1, a metal plural line clamping assembly 20 in general includes a stamped U-shaped top channel 22 and an opposed stamped U-shaped bottom channel 24. Of course, the channels could also be disposed vertically, in which case there would be right and left channels. The channels 22, 24 are formed with semi-cylindrical collars 26, 28 that support prior art junction adapters 30 at cylindrical collar support portions 32 formed on the junction adapter 30. It will be understood that the assembly shown in FIG. 1 is for example only and that there could be additional sets of semi-cylindrical collars 26, 28 further along the channel members 22, 24. As can be seen from the prior patents, the plural line clamping system 20 will typically have four to ten or more sets of semi-cylindrical collars 26, 28 with each collar set being adapted to mount a junction adapter 30. The prior art junction adapters 30 are formed having a hexagonal body portion 34, cylindrical collar support portions 32, and cylindrical portions 36. As shown in FIG. 1, even though the hexagonal body portions 34 within any one plural line clamping assembly are the same over-all size and the collar support portions 32 are the same size, the cylindrical portions 36 need not be the same size.
The hexagonal body portion 34 of each junction adapter 30 fits into the U-shaped channels 22, 24 and acts as a central support portion. Between the hexagonal body portion 34 and each cylindrical portion 36 is a collar support portion 32. Each cylindrical portion 36 has a threaded portion 38 formed on its outer surface. The junction adapter 30 is formed from a common piece of hexagonal bar stock. A fluid passage 40 passes through the entire extent of the junction adapter 30 and acts to create a passageway for fluid passing through lines sealingly connected to either cylindrical portion 36 of the junction adapter 30 and running to a machine actuator from a source of power, a control valve, or the like.
Cylindrical stacking nuts 42 having a predetermined length extend between the channels 22, 24 to separate the channels 22, 24 and secure each junction adapter 30 within the plural line clamping assembly 20, as is explained more fully below. Bolts 44 extend through holes 46 formed in the channels 22, 24 and are secured in screw thread holes 48 within the stacking nuts 42, as shown in FIGS. 1 and 2, to lock the channel members 22, 24 together and rigidly secure the junction adapters 30 within the plural line clamping assembly 20.
The hexagonal body portion 34 of each prior art junction adapter 30 fits within the plural line clamping assembly 20 between the channel members 22, 24 and stacking nuts 42. The junction adapter 30 forms line contacts at locations 50 between two opposed edges of the hexagonal body portion 34 and the channel members 22, 24. In addition, there is plane contact with the stacking nuts 42 along two opposed sides 52 of the hexagonal body portion 34. Since the hexagonal body portion 34 of each prior art junction adapter 30 has six equal faces or sides, an assembler merely needs to place the junction adapter 30 into the channel members 22, 24 and insert the bolts 44 into stacking nuts 42. Any two opposed sides 52 of the six sides of the junction adapter 30 can be oriented along the stacking nuts 42.
However, it can be seen in FIG. 2 that the hexagonal body portion 34 of the prior art hexagonal junction adapter 30 has an axial thickness T that is less than the width W between the opposed interior side walls of the channels 22, 24. Further, the cylindrical collar support portions 32 are formed at right angles to the hexagonal body portion 34 as shown at location 56. Therefore, a gap exists between the axial sides of the hexagonal body portion 34 of the junction adapter 30 and the channels 22, 24 which, at extremely high fluid line pressures, may allow the junction adapter 30 to shift its position within the clamping system 20.
The entire hexagonal junction adapter 30 of the prior art can be made out of commonly available hexagonal bar stock using standard automatic screw machines. Any suitable material can be used such as 1008 or 1010 mild steel. Hexagonal bar stock is readily available in a variety of SAE standard sizes that will correspond to the dimensions needed to have the hexagonal body portion 34 of the junction adapter 30 fit into the various sizes of channels 22, 24 of the plural line clamping systems 20. In other words, it is not necessary to machine the exterior surfaces, that is the sides 52, of the hexagonal body portion 34. For example, in making the prior art junction adapter 30, the hexagonal bar stock is machined in order to form the cylindrical collar support portions 32 and drilled ot to form the fluid passage 40. A threaded portion 38 is then formed on the two cylindrical portions 36.
Although the plural line clamping systems 20 shown in the prior patents have been very successful, there are some limitations. That is, there is an upper limit to the range of fluid line pressures over which the plural line clamping system 20 can operate. In particular, fluid line systems which have extremely high fluid line pressures may generate forces on the junction adapter 30 which may tend to cause the junction adapter 30 to shake or rattle in a plural line clamping system 20.
A necessary feature for any new plural line clamping system junction adapter is that it must be a retrofit into the existing plural line clamping systems. There are currently several tens of thousands of MULTI-CLAMP.RTM. installations in service in the United States and other countries, and each includes several collar pairs each supporting an adapter. Also, the manufacturer of MULTI-CLAMP.RTM. assemblies, its distributors and a number of their larger customers each maintain a substantial inventory of MULTI-CLAMP.RTM. systems or assemblies. In addition, conventional plural line clamping assemblies come in several different standard sizes of channels, with each different size channel requiring a different size body or central support section. To change the dimensions of the conventional plural line clamping assemblies would require tooling changes for each such size channel amounting to several millions of dollars for each different size. Thus, any new adapter must either fit into the existing plural line clamping assemblies or it will not be successful in the marketplace. It is not realistic to expect the industry to replace completed design or existing plural line clamping assemblies just in order to accommodate a new improved junction adapter.
In light of the foregoing discussion, it is a principal object of the present invention to provide a high quality one-piece junction adapter for use within a conventional plural line clamping system that improves the performance of the clamping system by enabling the clamping system to increase the upper limit on the range of fluid line pressures over which it may be successfully used. In particular, it is an important object to provide a junction adapter for a plural line clamping system that provides greater resistance to the forces resulting from extremely high fluid line pressures which tend to shake or rattle the junction adapter and thereby cause noise or further vibrations in the plural line clamping system.